Rheem 874W27NF Service Manual page 27

Fault-Finding Tests 5 - 7
Conduct test with no water flow.
Using a multimeter set on the DC volts scale,
measure the voltage between 3 Red and 2 Black
at terminal S on the control PCB.
Normal voltage should be between DC11 – 17V.
Remove the flow sensor turbine. Refer to „Flow Sensor Turbine‟ procedure on page 53.
Check for excessive wear of turbine or blockage by foreign material such as thread tape. The power
must be isolated during water flow sensor removal.
TM061 Rheem 27 Water Star Service Instructions – Issued: 11/10
REV A Issued 08/13
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Test 5
4
R 3
2
1
3
S 2
1
2
T
1
U 1
3
2
V
1
Water Volume
Control Assembly
Service. All printed copies not bearing this statement in RED are deemed "uncontrolled"
Conduct test with water flowing.
Using a multimeter set on the DC volts scale,
measure the voltage between 1 Brown and 2
Black at terminal S on the control PCB.
Normal voltage should be between DC2 – 5V.
Test 7
PGFR
Flow Sensor Turbine
Lock ring
Test 6
4
R 3
2
1
3
S 2
1
2
T
1
U 1
3
V 2
1
27